Browsing the claims on the Internet every day, I feel that it is not only college students who are fragile, but all human beings. For example, during the recent seafood season, there was a saying that people who were scratched by oyster shells had to have their limbs amputated - so what is on the shell of this kind of seafood? Are there really amputees?
What's on the oyster shell?
On the surface of these uneven shells, a bacteria called "Vibriovulnificus" is attached. "vulnificus" means wound.Under a light microscope, this bacterium looks like a comma and can be dyed purple. It does not seem to be much different from other Gram-negative bacteria (such as E. coli and salmonella). However, if we zoom in further, we will find that it drags a tail called a "flagella" and has some hair-like "piles" on its body. These structures help them move and stick together, and under a microscope they can be seen swimming quickly, like shooting stars.
Morphology of Vibrio vulnificus under light microscope
Morphology of Vibrio vulnificus under light microscope
As a halophilic member of the Vibrio family, Vibrio vulnificus is widely distributed under the warm sea surface in subtropical monsoon climates and is most abundant in July and August. Therefore, it is distributed in the coastal waters of China, Japan, South Korea, the United States, Mexico and other countries. Although Vibrio vulnificus was only discovered in the 1970s, Hippocrates had previously described it as a lethal condition. Vibrio vulnificus does not usually occur in cold, clean waters, but thrives in conditions of high chemical oxygen demand (COD, a measure of water pollution that chemically measures the amount of reducing substances in a water sample that need to be oxidized).
With global climate warming and human activities, the distribution area of Vibrio vulnificus has gradually expanded and moved northward, and people's risk of exposure is also increasing. Vibrio itself can cause food poisoning, and Vibrio vulnificus can also enter the body through wounds. This may be related to the capsule on its surface, which is like a layer of armor that prevents immune cells from functioning, and can also form a biofilm, just like the bacteria that cause tooth decay, to provide itself with a protective umbrella.
In addition, V. vulnificus has an iron metabolism pathway, and the large amount of iron in the blood may also be contributing to the problem, which also makes V. vulnificus infection greater in diseases that increase the body's iron content, such as sickle cell anemia, chronic liver disease, and hemochromatosis.
If Vibrio vulnificus infection enters the body through the gastrointestinal tract, it may only cause gastrointestinal reactions such as watery diarrhea and abdominal pain. However, if it enters the blood through the skin, the endotoxins in its structure can cause severe immune reactions, and some proteases can also cause damage to the body.
The skin of the patient's damaged area will first appear red and swollen, then begin to change color after necrosis, and then necrotizing fasciitis will occur. Patients often also suffer from severe hypotension.
According to statistics, 1 in 5 patients infected with Vibrio vulnificus will die. If antibiotic treatment is started 72 hours after infection, the mortality rate is almost 100%.So, to be honest, amputation is not a bad thing, but losing your life means nothing.
But there is no need to panic. There were so many grilled oyster stalls at the night market, but not many of them were sent to the hospital because they were wearing thick-threaded gloves. Considering that it can be exposed to infection, try to avoid natural waters when there are open wounds on the body. If necessary, you can put on a waterproof band-aid. After handling shellfish, it is recommended to wash hands with disinfectant (such as soapy water) regardless of whether there are wounds or not. If you feel uncomfortable, you should seek medical attention immediately.
Eating raw seafood will not only cause diarrhea
After talking about unintentional trauma, let’s talk about raw food that food lovers continue to challenge. I know everyone likes to eat something different, but I can’t help it, it’s delicious, and I have to eat puffer fish to the death. We are just trying to escape, but we still need to have some knowledge of risks. There is also a member of the halophilic Vibrio family called Vibrio parahaemolyticus. In fact, Vibrio has poor resistance to gastric acid and can be killed if ingested in small amounts.
However, in the case of raw food, there are definitely a lot of bacteria present, so there is a risk of food poisoning.
These pathogenic Vibrio bacteria will damage the villus structure of the small intestine that absorbs water and ions, affecting the body's water and salt balance. Patients will excrete large amounts of rice-like feces. If not treated in time, they may die of severe dehydration and electrolyte imbalance. If you are unlucky, the most serious consequences will be, of course, their bland (non-salt-loving) relative: Vibrio cholerae.
Raw food can not only cause bacterial infections, but also viral infections. The most famous of these is probably the hepatitis A outbreak in Shanghai in the late 1980s. The hairy clam is a common aquatic product. However, in its habits, it filters out the hepatitis A virus in the water and accumulates it in the body. Hepatitis A virus can be transmitted through the digestive tract. Although it has strong resistance to the outside world, it is not resistant to high temperatures. However, many people only scald it in boiling water and eat it with dipping sauce.
As a result, in the spring of 1988, approximately 300,000 people in Shanghai were infected with hepatitis A. Generally speaking, parasitic organisms in the ocean are unlikely to infect humans because the human environment is not suitable for them, but this is by no means impossible. Anisakis is the best example. After hatching in the water, relatives of this roundworm will enter fish and shrimp for further development. In the natural environment, their final hosts are marine mammals, such as sea lions and dolphins.
If accidentally ingested by humans, because humans are not suitable hosts and the roundworms have a habit of burrowing into holes, the larvae will cause severe gastrointestinal reactions, such as abdominal pain and nausea, as the larvae continue to move. Sometimes larvae migrans may occur, causing throat discomfort.
After the larvae die in the body, their body remains can also induce an immune response. Although not fatal, it is quite uncomfortable.
Of course, salmon and the like should have been processed and quarantined before being put on the market through formal channels, so you can rest assured.
Those freshly caught from the market, sprinkled with a bottle of white wine and vinegar or dipped in garlic mustard to sterilize them, are most likely to overturn.
So, next time you can’t help it, think twice~